<?php

namespace Mageplaza\HelloWorld\Events;

class ChangeTest implements \Magento\Framework\Event\ObserverInterface
{
    public function execute(\Magento\Framework\Event\Observer $observer)
    {
        $textDisplay = $observer->getData('mp_name');
        var_dump($textDisplay);
        echo $textDisplay->getName() . " - Event </br>";
        $textDisplay->setName("這個是二次購買的東西second");


        return $this;
    }
}